Content management systems may be limited in the quantity of assets that are available to end users. More specifically, end users of content management systems may access assets (e.g., image files, video files, multimedia files, and so forth) on local content repositories for use in web content such as web pages, advertisements, and so forth. Because storage is an expensive commodity, content management systems can benefit from an expanded quantity of assets such as those stored on external content repositories that are not managed by the administrators of the content management system.